воскресенье, 17 февраля 2019 г.

2019 February 17 Shadow of a Martian Robot Image Credit: Mars…

2019 February 17

Shadow of a Martian Robot
Image Credit: Mars Exploration Rover Mission, JPL, NASA

Explanation: What if you saw your shadow on Mars and it wasn’t human? Then you might be the Opportunity rover currently exploring Mars. Opportunity explored the red planet from 2004 to 2018, finding evidence of ancient water, and sending breathtaking images across the inner Solar System. Pictured here in 2004, Opportunity looks opposite the Sun into Endurance Crater and sees its own shadow. Two wheels are visible on the lower left and right, while the floor and walls of the unusual crater are visible in the background. Caught in a dust storm in 2018, last week NASA stopped try contact Opportunity and declare the ground-breaking mission, originally planned for only 92 days, complete.

∞ Source: apod.nasa.gov/apod/ap190217.html

Neanderthal footprints found in Gibraltar…

Neanderthal footprints found in Gibraltar http://www.geologypage.com/2019/02/neanderthal-footprints-found-in-gibraltar.html

Indonesia’s devastating 2018 earthquake was a rare supershear,…

Indonesia’s devastating 2018 earthquake was a rare supershear, UCLA study finds http://www.geologypage.com/2019/02/indonesias-devastating-2018-earthquake-was-a-rare-supershear-ucla-study-finds.html

New study of fossil plants shows the emergence of the Pacific…

New study of fossil plants shows the emergence of the Pacific Northwest’s temperate forests http://www.geologypage.com/2019/02/new-study-of-fossil-plants-shows-the-emergence-of-the-pacific-northwests-temperate-forests.html

New dinosaur with heart-shaped tail provides evolutionary clues…

New dinosaur with heart-shaped tail provides evolutionary clues for African continent http://www.geologypage.com/2019/02/new-dinosaur-with-heart-shaped-tail-provides-evolutionary-clues-for-african-continent.html

How undersea gases once helped superheat our planet…

How undersea gases once helped superheat our planet http://www.geologypage.com/2019/02/how-undersea-gases-once-helped-superheat-our-planet.html

Satellite images reveal interconnected plumbing system that…

Satellite images reveal interconnected plumbing system that caused Bali volcano to erupt http://www.geologypage.com/2019/02/satellite-images-reveal-interconnected-plumbing-system-that-caused-bali-volcano-to-erupt.html

Massive Bolivian earthquake reveals mountains 660 kilometers…

Massive Bolivian earthquake reveals mountains 660 kilometers below our feet http://www.geologypage.com/2019/02/massive-bolivian-earthquake-reveals-mountains-660-kilometers-below-our-feet.html

Insulating crust kept cryomagma liquid for millions of years on nearby dwarf planet

A recent NASA mission to the dwarf planet Ceres found brilliant, white spots of salts on its surface. New research led by The University of Texas at Austin in partnership with NASA’s Jet Propulsion Laboratory (JPL) delved into the factors that influenced the volcanic activity that formed the distinctive spots and that could play a key role in mixing the ingredients for life on other worlds.

Insulating crust kept cryomagma liquid for millions of years on nearby dwarf planet
The bright spots of Occator Crater shine from the surface of Ceres. Research led by The University of Texas at Austin
is helping reveal how the spots formed from cryomagma [Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA]

The volcanoes on Ceres are cryovolcanoes, a type of volcano that forms on planetary bodies with icy shells and that moves salty water known as cryomagma from underground reservoirs to the surface. Scientists think that cryovolcanoes on Jupiter’s icy moon Europa could help foster chemical mixing that could make complex molecules needed for life. Learning more about how these volcanoes work on Ceres–which is a simpler geological environment than Europa–could help scientists get a handle on the primary forces that drive their activity.

“Cryovolcanism looks to be a really important system as we look for life,” said lead author Marc Hesse, an associate professor at the UT Jackson School of Geosciences. “So we’re trying to understand these ice shells and how they behave.”

At 585 miles across, Ceres is the largest planetary body in the asteroid belt between Mars and Jupiter. Forged billions of years ago from rock and ice and far enough from the influence of other planets, scientists had thought that Ceres’ days of active geology had come to close. But the NASA Dawn mission changed that view when the space probe sent back pictures of bright, white spots at the bottom of impact craters. The spots turned out to be the remnants of cryomagma.

The location of the spots at or near the center of crater basins suggests that the heat and energy generated by asteroid impacts could jumpstart geology on Ceres, creating reservoirs of cryomagma that were then brought to the surface by conduits such as fractures.

The new research looked specifically at the deposits on the floor of the 90-mile-wide crater Occator, which was formed about 20 million years ago. However, the deposits here are as young as 4 million years old, indicating a relatively recent formation geologically speaking with respect to the crater itself. Earlier research conducted by other scientists found that the conditions on Ceres wouldn’t allow for the cryomagma generated by the Occator impact to exist for more than about 400,000 years.

Insulating crust kept cryomagma liquid for millions of years on nearby dwarf planet
Occator Crater on Ceres, with its central bright area called Cerealia Facula

The age discrepancy between salt deposits and impact timing raises a question: How could a reservoir of melt stay in a liquid state for millions of years after impact on an otherwise geologically stagnant world?

In their new paper, Hesse and Castillo-Rogez were able to significantly extend the life of the cryomagma by including more up-to-date details on Ceres’ crustal chemistry and physics.

“It’s difficult to maintain liquid so close to the surface,” said Castillo-Rogez. “But our new model includes materials inside the crust that tend to act as insulators consistent with the results from the Dawn observations.”

The new calculations indicate that the cryomagma of Occator could last up to 10 million years–a value that doesn’t close the time gap completely, but that indicates that the additional data helps make a more realistic cooling timeline.

“Now that we’re accounting for all these negative feedbacks on cooling–the fact that you release latent heat, the fact that as you warm up the crust it becomes less conductive–you can begin to argue that if the ages are just off by a few million years you might get it,” Hesse said.

Jennifer Scully, a planetary geologist at NASA’s JPL who studies Ceres but was not involved with the study, said that the findings are a great contribution toward unpacking the geologic history of an alien world.

“They used more up-to-date data to create their model,” said Scully. “This will help in the future to see if all of the material involved in the observed deposits can be explained by the impact, or does this require a connection to a deeper source of material. It’s a great step in the right direction of answering that question.”

The final version of the research was published in the journal Geophysical Research Letters.

Source: University of Texas at Austin [February 12, 2019]



New study suggests possibility of recent underground volcanism on Mars

A study published last year in the journal Science suggested liquid water is present beneath the south polar ice cap of Mars. Now, a new study in the AGU journal Geophysical Research Letters argues there needs to be an underground source of heat for liquid water to exist underneath the polar ice cap.

New study suggests possibility of recent underground volcanism on Mars
The Martian South Pole. A new study in Geophysical Research Letters argues there needs to be an underground
source of heat for liquid water to exist underneath the polar ice cap [Credit: NASA]

The new research does not take sides as to whether the liquid water exists. Instead, the authors suggest recent magmatic activity – the formation of a magma chamber within the past few hundred thousand years – must have occurred underneath the surface of Mars for there to be enough heat to produce liquid water underneath the kilometer-and-a-half thick ice cap. On the flip side, the study’s authors argue that if there was not recent magmatic activity underneath the surface of Mars, then there is not likely liquid water underneath the ice cap.

“Different people may go different ways with this, and we’re really interested to see how the community reacts to it,” said Michael Sori, an associate staff scientist in the Lunar and Planetary Laboratory at the University of Arizona and a co-lead author of the new paper.

The potential presence of recent underground magmatic activity on Mars lends weight to the idea that Mars is an active planet, geologically speaking. That fact could give scientists a better understanding of how planets evolve over time.

The new study is intended to further the debate around the possibility of liquid water on Mars. The presence of liquid water on the Red Planet has implications for potentially finding life outside of Earth and could also serve as a resource for future human exploration of our neighboring planet.

“We think that if there is any life, it likely has to be protected in the subsurface from the radiation,” said Ali Bramson, a postdoctoral research associate at the Lunar and Planetary Laboratory at the University of Arizona and a co-lead author of the new paper. “If there are still magmatic processes active today, maybe they were more common in the recent past, and could supply more widespread basal melting. This could provide a more favorable environment for liquid water and thus, perhaps, life.”

Examining the environment

Mars has two giant ice sheets at its poles, both a couple of kilometers thick. On Earth, it is common for liquid water to be present underneath thick ice sheets, with the planet’s heat causing the ice to melt where it meets the Earth’s crust.

In a paper published last year in Science, scientists said they detected a similar phenomenon on Mars. They claimed radar observations detected evidence of liquid water at the base of Mars’s south polar ice cap. However, the Science study did not address how the liquid water could have gotten there.

New study suggests possibility of recent underground volcanism on Mars
Schematic of the case considered in the new study causing a local elevated heat flux beneath Mars’s south polar ice cap.
The schematic shows a magma chamber of diameter D buried at a depth of H (to the center of the chamber) beneath
the putative liquid water, creating an elevated heat flux Q as it cools [Credit: AGU/GRL/Sori and Bramson]

Mars is much cooler than Earth so it was unclear what type of environment would be needed to melt the ice at the base of the ice cap. Although previous research has examined if liquid water could exist at the base of Mars’s ice caps, no one had yet looked at the specific location where the Science study claimed to have detected water.

“We thought there was a lot of room to figure out if [the liquid water] is real, what sort of environment would you need to melt the ice in the first place, what sort of temperatures would you need, what sort of geological process would you need? Because under normal conditions, it should be too cold,” Sori said.

Looking for the heat

The new study’s authors first assumed the detection of liquid water underneath the ice cap was correct and then worked to figure out what parameters were needed for the water to exist. They performed physical modeling of Mars to understand how much heat is coming out of the interior of the planet and if there could be enough salt at the base of the ice cap to melt the ice. Salt lowers the melting point of ice significantly so it was thought that salt could have led to melting at the base of the ice cap.

The model showed salt alone would not raise the temperature high enough to melt the ice. Instead, the authors propose there needs to be additional heat coming from Mars’s interior.

One plausible heat source would be volcanic activity in the planet’s subsurface. The study’s authors argue that magma from the deep interior of Mars rose towards the planet’s surface about 300,000 years ago. It did not break the surface, like a volcanic eruption, but pooled in a magma chamber below the surface. As the magma chamber cooled, it released heat that melted the ice at the base of the ice sheet. The magma chamber is still providing heat to the ice sheet to generate liquid water today.

The idea of volcanic activity on Mars is not new – there is a lot of evidence of volcanism on the planet’s surface. But most of the volcanic features on Mars are from millions of years ago, leading scientists to believe volcanic activity below and above the planet’s surface stopped long ago.

The new study, however, proposes that there could have been more recent underground volcanic activity. And, if there was volcanic activity happening hundreds of thousands of years ago, there’s a possibility it could be happening today, according to the study’s authors.

“This would imply that there is still active magma chamber formation going on in the interior of Mars today and it is not just a cold, sort of dead place, internally,” Bramson said.

Jack Holt, a professor at the at the Lunar and Planetary Laboratory at the University of Arizona, said the question of how water could exist underneath the south polar ice cap immediately came to his mind after the Science paper was published, and the new paper adds an important constraint on the possibility of water being there. He said it will likely add to the debate in the planetary science community about the finding and point out that more research needs to be done to evaluate it.

“I think it was a great idea to do this type of modeling and analysis because you have to explain the water, if it’s there, and so it’s really a critical piece of the puzzle,” said Holt, who was not involved in the new research but did talk to the study’s authors before they submitted the paper. “The original paper just left it hanging. There could be water there, but you have to explain it, and these guys did a really nice job of saying what is required and that salt is not sufficient.”

Source: American Geophysical Union [February 12, 2019]



Longest-ever eDNA study offers important insights into ocean health

Tiny genetic ‘breadcrumbs’ left behind by marine organisms offer unprecedented insights into ocean biodiversity and how it changes over time and in response to our changing climate, new research at Curtin University, in collaboration with CSIRO, has revealed.

Longest-ever eDNA study offers important insights into ocean health
Sampling for plankton and eDNA using a net [Credit: IMOS-CSIRO/Julian Uribe]

Researchers developed new environmental DNA (eDNA) biomonitoring methods using samples collected off the coast of Rottnest Island near Perth, Western Australia, as part of Australia’s Integrated Marine Observing System (IMOS).

IMOS scientists collected and froze filtered seawater samples over a five-year period. These ‘time capsules’ provided a unique opportunity to study changes in our oceans and marine life that occur seasonally and in response to climate anomalies such as the marine heatwave that struck WA in 2011.

The study, published in journal PLOS Genetics, demonstrated how a zooplankton community – the larvae and eggs of fish – responds normally to seasonal change in contrast to heatwave conditions.

The study is the longest multi-year marine eDNA study yet conducted and showcases the power of eDNA technologies to monitor our ocean health.

Ph.D. student Tina Berry and Professor Michael Bunce, from Curtin’s School of Molecular and Life Sciences, led the research team.

“It is incredibly rare to find a series of samples from such a long time period that are also suitable for DNA analysis,” Ms Berry said.

“The scientists at IMOS had the foresight to biobank a set of samples that allowed us to travel back through time and see how the ocean responded to a marine heatwave.

“After some hard work in the lab to isolate and sequence the DNA, a significant and revealing story appeared. The end result was a holistic window into our marine life that would otherwise be impossible to see.”

Professor Bunce said environmental DNA was fast emerging as an effective way to study our oceans and the technique hit the headlines in 2018 as researchers went searching for the Loch Ness Monster using eDNA.

“We didn’t find any monsters either, unless you count two samples with trace amount of humpback whale in them. But to be honest, it’s the small creatures that live in our oceans that provide the greatest clues to our ocean’s wellbeing.”

Professor Bunce said the eDNA signatures mapped out which marine organisms were present at different times of the year and identified those that first appeared when sea surface temperatures spiked during the heatwave.

“Being able to track thousands of marine species at a time using eDNA offers important clues regarding how our oceans are changing as they warm, it’s a glimpse into the future that we can’t see using other methods,” Professor Bunce said.

“Australia has the Earth’s third largest ocean territory and every year the nation derives an estimated $47.2 billion from its ‘blue economy’ so understanding how it is changing is of high national importance.

“Using eDNA, we are detecting sharks, corals, seahorses and marine mammals and the DNA toolkit we are developing in our wider research program is a road-map for long-term ocean monitoring around the world. We urgently need better ways to perform health-checks on our marine environments and eDNA is responding to this need.”

Source: Curtin University [February 12, 2019]



Uncovering the evolution of the brain

What makes us human, and where does this mysterious property of “humanness” come from? Humans are genetically similar to chimpanzees and bonobos, yet there exist obvious behavioral and cognitive differences. Now, researchers from the Salk Institute, in collaboration with researchers from the anthropology department at UC San Diego, have developed a strategy to more easily study the early development of human neurons compared with the neurons of nonhuman primates. The study, which is published in eLife, offers scientists a novel tool for fundamental brain research.

Uncovering the evolution of the brain
A stylized microscopy image of forebrain neural progenitor cells from chimpanzees described in the publication.
The image represents the work’s potential for offering insights into the evolution of the primate tree of life
[Credit: Salk Institute/Carol Marchetto/Ana P.D. Mendes]

“This study provides insights into the developmental organization of the brain and lays the groundwork for further comparative analyses between humans and nonhuman primates,” says one of the senior authors of the study, Salk President and Professor Rusty Gage, who holds the Vi and John Adler Chair for Research on Age-Related Neurodegenerative Disease.

Two important processes in brain development include neuron maturation and migration. Maturation involves neuron growth as the neurons increase their connections between each other for better communication. Migration is the physical movement of neurons into different parts of the developing brain. The authors sought to compare neuron maturation and migration between humans and nonhuman primates.

To accomplish this task, the Gage lab devised a new method utilizing stem cell technology to take skin cells from primates and coax them, via a virus and chemical cocktails, to develop into neural progenitor cells, a cell type that has the ability to become multiple types of cells in the brain, including neurons. These new primate cell lines can then be perpetually propagated, allowing researchers new avenues to study aspects of neuronal development of live neurons without tissue samples from endangered primates such as chimpanzees and bonobos.

“This is a novel strategy to study human evolution,” says Carol Marchetto, a Salk senior staff scientist in the Laboratory of Genetics, co-first author and one of the study’s senior authors. “We are happy to share these primate cell lines with the scientific community, so that researchers from around the world can examine primate brain development without the use of tissue samples. We anticipate this will lead to numerous new findings over the next few years about the brain’s evolution.”

The researchers first explored the differences in gene expression related to neuronal movement, comparing human, chimpanzee and bonobo cells. They also investigated the migration properties of the neurons inherent to each species. They found 52 genes related to migration, and, interestingly, chimpanzee and bonobo neurons had periods of rapid migration, while human neurons were slow to move.

In order to compare neuron movement and maturation outside of a dish, the scientists transplanted the neural progenitor cells from both humans and chimpanzees into the brains of rodents, enabling the neurons to thrive and providing additional developmental cues for the neurons to develop.

The researchers then analyzed the differences in migration distance, shape and size of the neurons for up to 19 weeks after transplantation. They observed the length, density and quantity of extensions of the neurons called dendrites, as well as the size of the cell bodies, which house the nucleus and DNA.

The chimpanzee neurons migrated a greater distance and covered a 76 percent greater area than the human neurons after two weeks. Human neurons were slower to develop but reached longer lengths than the chimpanzee neurons. This slower growth pattern may allow humans to reach more developmental milestones than nonhuman primates, which could account for differences in behavior and cognitive abilities.

In the future, the authors hope to construct an evolutionary tree of multiple primate species, utilizing induced pluripotent stem cell lines, to better understand of the evolution of the human brain. In addition, the authors plan to use this platform to study gene regulation differences between primate species that underlie the differences in neuronal maturation and can potentially impact brain organization in humans.

“We have limited knowledge about the evolution of the brain, especially when it comes to differences in cellular development between species,” says Marchetto. “We’re excited about the tremendous possibilities this work opens up for the field of neuroscience and brain evolution.”

Source: Salk Institute [February 12, 2019]



Medieval archive reveals how nun faked her own death to escape convent

A nun who faked her own death, an archbishop who went into battle with an army of clergymen, and why being a priest was the most dangerous job of the Middle Ages: these are just some of the stories beginning to emerge from fourteenth-century records held in the University of York’s archives.

Medieval archive reveals how nun faked her own death to escape convent
Archbishop’s register reveals how Joan of Leeds crafted a dummy of her body that was buried, while she pursued
‘the way of carnal lust’ [Credit: Nancy Bauer/Shutterstock]

Joan of Leeds was fed up of her life in a medieval nunnery. By 1318, her urge to escape the vows she had pledged to poverty, chastity and obedience had grown so strong that she resorted to faking her own death.

After tricking her fellow sisters into burying a dummy they believed to be her body, Joan fled. But alas, her freedom was short lived as she was soon discovered and ordered to return to the convent by the Archbishop of York.

Archivists from the Borthwick Institute for Archives at the University of York have uncovered Joan’s story as they begin to explore registers recording the business of the archbishops of York between 1304 and 1405.


Ink, skilfully scrawled onto parchment by medieval scribes, preserves the secrets of people – from nobles to peasants and bishops to curates – who lived during periods of disease, war, famine, political strife and religious reformation in the King’s City in the North and surrounding province.

Before coming into the University’s care, the 16 heavy volumes had endured a perilous existence and have not been extensively studied. In the Middle Ages they were carried by the Archbishop’s officials on his travels; after the English Civil War they found their way to storage in London, only being restored to the Diocesan Registry in York Minster in the late eighteenth century. Parts of some registers have been published, but often untranslated from the original Latin.

Now, with an injection of just under £1m of funding from the Arts and Humanities Research Council, a research team of medieval historians and archivists from the University and The National Archives (UK) are taking on the painstaking task of translating the volumes and indexing them to make their contents digitally available to all for free.

Rich account

“Archbishops of York in the fourteenth century had incredibly varied roles,” explains Professor Sarah Rees Jones, medieval historian at the University of York and Principal Investigator on the project.

Medieval archive reveals how nun faked her own death to escape convent
The register that details the story of Joan of Leeds [Credit: University of York]

“On the one hand they carried out diplomatic work in Europe and Rome and rubbed shoulders with the VIPs of the Middle Ages. However, they were also on the ground resolving disputes between ordinary people, inspecting priories and monasteries and correcting wayward monks and nuns.

“That’s why these Registers provide such a rich account of people from all walks of fourteenth-century life during a fascinating and extremely turbulent period.”

Priest army

Over the course of their research, the team is hoping to find out more about some of history’s most extraordinary archbishops – characters such as William Melton, who led an army of priests and citizens into battle to defend the City of York against the Scots in 1319.

“In the Middles Ages, York was an extremely important northern city on the frontline of the Scottish wars of independence,” says Professor Rees Jones. “But unfortunately the fight didn’t go well for Melton and his army of clergy. Their lack of military training resulted in a reported 4,000 men dying on the battlefield and a further 1,000 are believed to have drowned in the River Swale trying to escape.”

Not all archbishops of York documented by the registers were such loyal subjects to their kings. Archbishop Richard le Scrope was executed in 1405 for his participation in the Northern Rising against Henry IV – an act immortalised in the eponymous Shakespeare play. “The records may well provide more information on this episode and offer some fresh insights into Scrope’s motivations for getting involved,” Professor Rees Jones adds.

Black Death

The registers also chronicle the Black Death which swept through Europe from 1347 to 1351 and wiped out 60% of the British population. “The equivalent would be if 40 million people died in Britain today within the space of around four years” says Professor Rees Jones. “There were empty monasteries and entire villages were decimated.”

Medieval archive reveals how nun faked her own death to escape convent
Gary Brannan, Archivist, and Professor Sarah Rees Jones examine one of the registers
[Credit: University of York]

“Being a priest was one of the most dangerous jobs in Europe during that time as they visited the sick and administered last rites at death beds.”

New light

However, the Black Death did bring about important change in the church. “Because so many priests had died there weren’t enough people trained in Latin, so delivering sermons in English had to be adopted as the new status quo,” Professor Rees Jones adds.

“The registers may shed new light on what it was like to live through this period and will perhaps give us a sense of how the Church reasserted its authority after such catastrophic events.”

The project, called ‘The Northern Way’ will run for 33 months in partnership with The National Archives (UK) and with the support of the Chapter of York Minster. The team will also generate a programme of lectures, publications and joint research with local history groups and postgraduate students.

Northern identity

Once indexed, the material from the registers will be linked via the York’s Archishops’ Registers Revealed platform to ecclesiastical records at The National Archives, the British Library and York Minster to provide a complete picture of the role of the northern archbishops in national affairs.

“These chronicles will give us a window into the lives of important figures and ordinary people,” Professor Rees Jones says. “Their revelations may change our perception of northern identity and parts of history as we know it.”

Source: University of York [February 12, 2019]



Giant ‘megalodon’ shark extinct earlier than previously thought

Megalodon – a giant predatory shark that has inspired numerous documentaries, books and blockbuster movies – likely went extinct at least one million years earlier than previously thought, according to new research published in PeerJ.

Giant 'megalodon' shark extinct earlier than previously thought
Megalodon extinction graphical abstract [Credit: Robert Boessenecker]

Earlier research, which used a worldwide sample of fossils, suggested that the 50-foot-long, giant shark Otodus megalodon went extinct 2.6 million years ago. Another recent study attempted to link this extinction (and that of other marine species) with a supernova known to have occurred at about this time.

However, a team of researchers led by vertebrate paleontologist Robert Boessenecker with the College of Charleston, Charleston, South Carolina, noted that in many places there were problems with the data regarding individual fossils in the study estimating the extinction date.

In the new study, the researchers reported every fossil occurrence of O. megalodon from the densely sampled rock record of California and Baja California (Mexico) in order to estimate the extinction.

Besides Boessenecker, the research team included Dana Ehret, of New Jersey State Museum; Douglas Long, of the California Academy of Sciences; Morgan Churchill, of the University of Wisconsin Oshkosh; Evan Martin, of the San Diego Natural History Museum; and Sarah Boessenecker, of the University of Leicester, United Kingdom.

They found that genuine fossil occurrences were present until the end of the early Pliocene epoch, 3.6 million years ago. All later fossils either had poor data provenance and likely came from other fossil sites or showed evidence of being eroded from older deposits. Until 3.6 million years ago, O. megalodon had a continuous fossil record on the West Coast.

“We used the same worldwide dataset as earlier researchers but thoroughly vetted every fossil occurrence, and found that most of the dates had several problems-fossils with dates too young or imprecise, fossils that have been misidentified, or old dates that have since been refined by improvements in geology; and we now know the specimens are much younger,” Boessenecker said.

“After making extensive adjustments to this worldwide sample and statistically re-analyzing the data, we found that the extinction of O. megalodon must have happened at least one million years earlier than previously determined.”

This is a substantial adjustment as it means that O. megalodon likely went extinct long before a suite of strange seals, walruses, sea cows, porpoises, dolphins and whales all disappeared sometime about 1-2.5 million years ago.

“The extinction of O. megalodon was previously thought to be related to this marine mass extinction-but in reality, we now know the two are not immediately related,” Boessenecker said.

It also is further unclear if this proposed mass extinction is actually an extinction, as marine mammal fossils between 1 and 2 million years old are extraordinarily rare-giving a two-million- year-long period of “wiggle room.”

“Rather, it is possible that there was a period of faunal turnover (many species becoming extinct and many new species appearing) rather than a true immediate and catastrophic extinction caused by an astronomical cataclysm like a supernova,” Boessenecker said.

The researchers speculate that competition with the newly evolved modern great white shark (Carcharodon carcharias) is a more likely reason for megalodon’s extinction.

Great whites first show up with serrated teeth about 6 million years ago and only in the Pacific; by 4 million years ago, they are finally found worldwide.

“We propose that this short overlap (3.6-4 million years ago) was sufficient time for great white sharks to spread worldwide and outcompete O. megalodon throughout its range, driving it to extinction-rather than radiation from outer space,” Boessenecker said.

Source: University of Wisconsin Oshkosh [February 13, 2019]



Skeleton of teenage girl found buried alongside two bull skulls at Egypt’s Meidum...

Egyptian archaeologists excavating the ruins of a pyramid 60 miles outside of Cairo have discovered the skeletal remains of a 13-year-old girl huddled inside a tomb.

Skeleton of teenage girl found buried alongside two bull skulls at Egypt's Meidum pyramid
The skeleton of a 13-year-old girl was discovered in a cemetery next to a 4,600-year-old
pyramid at Meidum in Egypt [Credit: Egypt. Ministry of Antiquities]

Exactly how or when she died is a mystery, though the experts say the site itself dates back to the end of the Third Dynasty roughly 4,600 years ago.
The tomb was empty apart from the skeleton, which was buried in the squatting position, but the team also found two animal skulls and three ceramic vessels nearby that were likely placed as funerary offerings.

Skeleton of teenage girl found buried alongside two bull skulls at Egypt's Meidum pyramid
The skulls of two bulls, used as funerary offerings, were found near the grave of the girl
[Credit: Egypt. Ministry of Antiquities]

The skull offerings appear to have come from bulls, according to Egypt’s Ministry of Antiquities.
Researchers came across the burial during work on the partially-collapsed Meidum pyramid, where the team is excavating a cemetery built near the end of the Third Dynasty.

Skeleton of teenage girl found buried alongside two bull skulls at Egypt's Meidum pyramid
The skulls of the two sacrificed bulls [Credit: Egypt. Ministry of Antiquities]

It’s thought that construction on the Meidum period began at the command of the Third Dynasty’s last pharaoh, Huni, and was continued by Sneferu, the first pharaoh of the Fourth Dynasty.
Previous efforts at the site uncovered the tomb of Prince Nefar-Maat, Sneferu’s oldest son.

Skeleton of teenage girl found buried alongside two bull skulls at Egypt's Meidum pyramid
Three ceramic vessels were also found beside the animal sacrifices
[Credit: Egypt. Ministry of Antiquities]

While the newly-discovered bones indicate the remains belong to a girl who was around 13 years old when she died, much about the burial and the offerings are still unclear.
Researchers do not know the identity of the buried teenager.

Skeleton of teenage girl found buried alongside two bull skulls at Egypt's Meidum pyramid
Remains of brick wall found near the cemetery [Credit: Egypt. Ministry of Antiquities]

The latest burial was found surrounded by a partially intact brick wall, and the team is now working to restore and reinforce the structures.

Author: Cheyenne MacDonald | Source: Daily Mail [February 13, 2019]



Radiocarbon dates show the origins of megalith graves and how they spread across Europe

How did European megalith graves arise and spread? Using radiocarbon dates from a large quantity of material, an archaeologist at the University of Gothenburg has been able to show that people in the younger Stone Age were far more mobile than previously thought, had quite advanced seafaring skills, and that there were exchanges between different parts of Europe.

Radiocarbon dates show the origins of megalith graves and how they spread across Europe
The megalithic grave Dolmen de Fontanaccia, Corsica
[Credit: Bettina Schulz Paulsson]

Bettina Schulz Paulsson’s study has been published in the Proceedings of the National Academy of Sciences. With the aid of modern technology, she has been able to answer a question which has occupied researchers for over a hundred years: How and where did megalith graves arise?
Today, there are approximately 35,000 megaliths – ancient monuments constructed from one or more blocks of stone – that remain all across Europe. Most of them come from the Neolithic period (the final part of the Stone Age) and the Copper Age (the transition period between the Neolithic period and the Bronze Age) and are concentrated in coastal areas.

Radiocarbon dates show the origins of megalith graves and how they spread across Europe
The Dolmen di Sa Coveccada megalithic grave, Sardinia
[Credit: Bettina Schulz Paulsson]

The question scientists have long been asking is whether the tradition of constructing megalith graves spread across Europe from a single point of origin, or if this tradition arose at different locations, independent of each other.
More than 2,400 radiocarbon dates

Bettina Schulz Paulsson, who is an archaeologist at the University of Gothenburg, has analysed more than 2,400 radiocarbon dates from megalithic, pre-megalithic and contemporaneous non-megalithic sites throughout Europe, which she collected over a 10-year period in the research literature and on field trips.

Radiocarbon dates show the origins of megalith graves and how they spread across Europe
A megalithic enclosure on Er Lannic Island in the Gulf of Morbihan in Brittany, France
[Credit: Loic Venance/AFP — Getty Images]

The earliest megalith graves arose 6,500 years ago over a period of 200-300 years in Northwest France, along the Atlantic coast of the Iberian Peninsula, and in the Mediterranean region.
Pre-megalithic structures were found only in Northwest France. Megalith graves emerge on the Iberian Peninsula, in the British Isles and in France in the first half of the 5th millennium BCE, and in Scandinavia during the second half of the same millennium.

Radiocarbon dates show the origins of megalith graves and how they spread across Europe
A Megalithic grave on the north coast of Brittany [Credit: Bettina Schulz Paulsson]

In the early 20th century, researchers such as Oscar Montelius and Gordon Childe assumed that the megaliths had developed in one region (although they disagreed on where) and then spread from there. But apart from these two, until now the scientific community had thought and assumed that the construction of megalith monuments developed independently in five separate regions.
Diffused via sea routes

For the first time, Bettina Schulz Paulsson’s study establishes that this practice was not developed in and then spread from different places independently of each other – and also where the first ones were constructed.

Radiocarbon dates show the origins of megalith graves and how they spread across Europe
The stone circle Ring of Brodgar on the Orkney Islands, Scotland
[Credit: Bettina Schulz Paulsson]

“My results show that Northwest France was where Europe’s first megalith graves arose and that the megalith tradition then gradually diffused in largely three phases. All in all, the results indicate that there was great mobility via sea routes,” says Bettina Schulz Paulsson.

“This is the first time that this has actually been shown. The distribution of these graves suggests that the megalith tradition was diffused via sea routes. The maritime skills and technologies of megalithic societies appear to have been more advanced than previously thought,” says Bettina Schulz Paulsson.

Source: University of Gothenburg [February 14, 2019]



Stunning Narcissus fresco uncovered at Pompeii

A stunning fresco depicting Narcissus gazing at his own reflection has been uncovered during new excavations at Pompeii, the interim director of the archaeological site, Alfonsina Russo, announced on Thursday.

Stunning Narcissus fresco uncovered at Pompeii
Credit: Archaeological Park of Pompeii

Pompeii Superintendent Massimo Osanna said the myth of Narcissus was a “very commonly found artistic topos in the ancient city”.
He said “the whole ambience is pervaded by the theme of ‘joie de vivre’, beauty and vanity, underscored also by the figures of maenads and satyrs who, in a sort of Dionysian courtship dance, accompanied the visitors inside the public part of the ancient house.

Stunning Narcissus fresco uncovered at Pompeii

Stunning Narcissus fresco uncovered at Pompeii

Stunning Narcissus fresco uncovered at Pompeii
Credit: Archaeological Park of Pompeii

“It is a deliberately luxurious, and probably dating back to the last years of the colony, as is testified by the extraordinary state of conservation of the colours”.
The discovery was made during a dig at the Regio V section of the ancient Roman city and comes just months after the unearthing of another specular fresco, depicting Jupiter taking the form of a swan to impregnate Spartan queen Leda. “The beauty of these rooms have led us to change our project and continue the excavation,” Russo said. “In the future it will be possible to open up at least a part of this domus for the public to enjoy”. “Refined decorations of the fourth style characterise the entire Room of Leda,” the archaeologists who made the discovery told reporters.

Stunning Narcissus fresco uncovered at Pompeii

Stunning Narcissus fresco uncovered at Pompeii

Stunning Narcissus fresco uncovered at Pompeii
Credit: Archaeological Park of Pompeii

“Delicate floral ornamental elements, interspersed with griffins and cornucopia, flying cherubs, still lifes and scenes of animals fighting abound”, they said.
The “harmony of these precious designs extended up to the ceiling, which collapsed in ruins under the wight of the volcanic stones called lapilli, but the fragments have been recovered by restorers who will put them back together,” they said.

Stunning Narcissus fresco uncovered at Pompeii

Stunning Narcissus fresco uncovered at Pompeii

Stunning Narcissus fresco uncovered at Pompeii
Credit: Archaeological Park of Pompeii

“Also very interesting, in the atrium of Narcissus, is the still visible trace of a staircase that led to the floor above, but above all the discovery in the space of a the stairwell, which was used as a store room, of a dozen glass containers, eight amphorae and a bronze funnel,” the archaeologists told reporters. “Then, there is a bronze ‘situla’ (container for liquids) which was discovered next to the impluvium”.

Narcissus, in Greek mythology, was the son of a river god and a nymph who was distinguished for his striking beauty. According to Ovid’s Metamorphoses, Book III, Narcissus’s mother was told by the blind seer Tiresias that he would have a long life, provided he never recognized himself. However, his rejection of the love of the nymph Echo drew upon him the vengeance of the gods. He fell in love with his own reflection in the waters of a spring and pined away, or killed himself; the flower that bears his name sprang up where he died.

Source: ANSA [February 14, 2019]




https://t.co/hvL60wwELQ — XissUFOtoday Space (@xufospace) August 3, 2021 Жаждущий ежик наслаждается пресной водой после нескольких дней в о...